Transcript Belanger OLLI week1 final - Denver Climate Study Group

Earth’s Climate: Past, Present and Future – concerns
and solutions
Paul Belanger, Ph.D.
Geologist/Paleoclimatologist
week 1: 3/30/2016
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Introductions
Key principles of climate change
The difference between weather and climate
Climate system: feedbacks, cycles and self-regulation
(climate, not government)
• What determines Earth’s climate
Intro:
• Intro:
• Yourselves – what brought you here
• my background, ramblings
• web page
http://denverclimatestudygroup.com/
(OLLI tab) and Facebook
• CV (about tab)
• Logistics
• Paula Morgan: classroom assistant, liaison
to me/OLLI
Intro:
Going to:
• web page:
http://denverclimatestudygroup.com/
• Facebook too – blog:
https://www.facebook.com/denverclimate
studygroup/?fref=ts
“In this age of specialization, men
who thoroughly know one field are
often incompetent to discuss another.
. . . You must not fool yourself--and
you are the easiest person to fool”
Richard Feynman, 1974
My comment:
We’ve become a country of selfproclaimed experts on everything.
Three books to consider:
• Simple succinct Summary:
– What We Know About Climate Change (Boston Review
Books) by Kerry Emanuel (Nov 30, 2012)
• Intermediate Level Book:
– Earth: The Operators' Manual by Richard B. Alley (Apr 18,
2011)
–
http://earththeoperatorsmanual.com/
• More comprehensive book:
Experimenting on a Small Planet: A Scholarly
Entertainment by William W. Hay (Dec 14, 2012)
Another book to consider:
• Economics:
– Climate Shock; the economic consequence of a
hotter planet
– by Gernot Wagner & Martin Weitzman
• If you had a 10 percent chance of having a fatal car
accident, you'd take necessary precautions. If your finances
had a 10 percent chance of suffering a severe loss, you'd
reevaluate your assets. So if we know the world is warming
and there's a 10 percent chance this might eventually lead
to a catastrophe beyond anything we could imagine, why
aren't we doing more about climate change right now? We
insure our lives against an uncertain future--why not our
planet?
• In Climate Shock, Gernot Wagner and Martin Weitzman
explore in lively, clear terms the likely repercussions of a
hotter planet, drawing on and expanding from work
previously unavailable to general audiences. …..
We need a Paradigm shift
• Which led to my email quote from Kerry
Emanuel and the need for a social paradigm
shift:
• “…there are few, if any, historical examples of
civilizations consciously making sacrifices on
behalf of descendants two or more
generations removed”
• Recent discussions for a new Presidential
candidate: Secretary of the future
VIDEO - what is climate
• https://www.futurelearn.com/courses/climate
-change-challenges-and-solutions/todo/123
• And go to 1.4
How we receive and transmit energy in
the form of light
• Visible vs. Infrared/longer wave – a function of “black
body” temperature: instead of glass keeping the heat
in it’s the gas properties keeping the heat of infrared
in; blanket effect.
What determines Earth’s climate
INTRODUCTION: Definitions:
•First order Forcings: EXTERNAL Influences (3):
SOLAR input:
0.9% less
100 My ago
Obliquity
Tilt; 40,000 years:
21.5 – 24.5 degrees
Precession
Eccentricity
20,000 years:
summer season
100,000 years
Atmospheric Opacity
(gases that absorb radiation in or out)
Albedo
(refletivity:30-85%)
•Feedbacks: INTERNAL dynamics and responses
•e.g. higher water vapor in atm. due to heating of atm
Milankovitch
~= 3-8 W/m2
Sunspots ~=
0.3 – 0.5 W/m2
DOUBLING: 280
to 560 ppm CO2 =
~ 3 W/m2
Referred to as
climate
sensitivity
Current
GHGs ~=
1.6W/m2
http://www.skepticalscience.com/Milankovitch.html
THE SUN’S ROLE IS MINIMIZING
GREENHOUSE GASES (GHGs)
– Water – H2O – the amount is a feedback of
temperature held in by the “blanket” of other
GHGs
– Carbon dioxide - CO2
– Methane - CH4
– Ozone - O3
– Nitrous oxide- N2O
– others
The CO2 greenhouse gas effect is concentrated
TheThe
mostEarth
potentand
greenhouse
gas is H2O - vapor
its atmosphere
in the polar regions ! ! !
Particularly
The large H2in
O the
greenhouse
effect
Arctic
!
is controlled by
temperature –
H2O saturation doubles
CO2 and other
with every
Greenhouse gases
10°C Increase
are evenly distributed
throughout the
As a result It is
atmosphere
concentrated in
the lower atmosphere
of the tropics
0.8562 m3
(95 cm x 95 cm x 95 cm)
@ 30oC +1oC
= 8%
increase in
vapor
10oC =
(50oF)
7.8 cc
20oC =
(68oF)
15 cc
30oC =
(86oF)
27.7 cc
40oC =
(104oF)
49.8 cc
How GHGs Blanket the Earth
• Blanket Earth:
• http://climate.nasa.gov/causes/
• https://www.youtube.com/watch?v=aqkGoCgl
p_U&feature=youtu.be
• https://www.youtube.com/watch?v=we8VXw
a83FQ
Absorption of Radiation by Greenhouse Gases
Incoming
Radiation
5700 K
Outgoing
Radiation
289 K
3: EMISSIONS FROM HUMAN ACTIVITIES
LARGELY TO BLAME
• 40% increase in CO2
• Dead carbon altering atmospheric C14
• That Carbon is more negative/enriched in C12
GLOBAL WARMING CONCERNS
Incoming Solar irradiance: 342 W/m2
IPCC, 2007
1: THE CLIMATE IS WARMING
• Drivers; aka forcings, i.e. causes
5: SURFACE TO STRATOSPHERE CHANGES
Only ~2% stays
in atmosphere
~2% warms
the land
Melting ice
absorbs ~2%
John Cook, from IGPP 2007 data; ~93% to oceans continues (NOAA/NODC, 2012)
Change in heat content, 1958-2011
20
5-year moving averages
Oceans, 0-700 m depth
1022 Joules
15
Oceans, 700-2000 m depth
10
5
(Increasing heat, not
shown, goes deeper
than 2000 m)
0
-5
1960
Atmosphere + land + ice melting
1970
1980
1990
2000
(NOAA 2012 data, Nuccitelli et al. 2012 plot)
http://www.skepticalscience.com/graphics.php?g=47
The Pacific –
‘normal condition’
El Niño
-4
La Niña
-2
0
2
4
Temperature
Anomaly °C
12. ARCTIC ICE vs. ANTARCTIC SEA ICE
• Ans. More moisture in air around Antarctica (AA) to
nucleate sea ice
• Despite > AA is does not compensate for Arctic loss
2015
http://nsidc.org/arcti
cseaicenews/2015/
http://nsidc.org/arcticseaicenews/2015/
For more see: http://www.skepticalscience.com/melting-ice-globalwarming.htm
http://nsidc.org/arcti
cseaicenews/2015/
14: HOW FAST IS SEA LEVEL
RISING?
Blue: Sea level change from tide-gauge data (Church J.A. and White N.J., Geophys. Res. Lett. 2006; 33: L01602)
Red: Univ. Colorado sea level analyses in satellite era (http://www.columbia.edu/~mhs119/SeaLevel/).
Loaded Climate Dice: global warming is increasing extreme weather events.
Extreme summer heat anomalies now cover about 10% of land area, up from 0.2%.
This is based on observations, not models.
Frequency of occurrence (vertical axis) of local June-July-August temperature anomalies
(relative to 1951-1980 mean) for Northern Hemisphere land in units of local standard
deviation (horizontal axis). Temperature anomalies in the period 1951-1980 match closely the
normal distribution ("bell curve", shown in green), which is used to define cold (blue), typical
(white) and hot (red) seasons, each with probability 33.3%. The distribution of anomalies has
shifted to the right as a consequence of the global warming of the past three decades such that
cool summers now cover only half of one side of a six-sided die, white covers one side, red
covers four sides, and an extremely hot (red-brown) anomaly covers half of one side.
Source: Hansen, J., Sato, M., and Ruedy, R., Proc. Natl. Acad. Sci., 2012.
End of week 1